title: Ageing of atrazine in manure amended soils assessed by bioavailability to Pseudomonas sp. strain ADP.
abstract: Animal manure is applied to agricultural land in areas of high livestock production. In the present study, we evaluated ageing of atrazine in two topsoils with and without addition of manure and in one subsoil. Ageing was assessed as the bioavailability of atrazine to the atrazine mineralizing bacteria Pseudomonas sp. strain ADP. Throughout an ageing period of 90 days bioavailability was investigated at days 1, 10, 32, 60 and 90, where ~10(8) cells g(-1) of the ADP strain was inoculated to the (14)C-atrazine exposed soil and (14)CO2 was collected over 7 days as a measure of mineralized atrazine. Even though the bioavailable residue decreased in all of the three soils as time proceeded, we found that ageing occurred faster in the topsoils rich in organic carbon than in subsoil. For one topsoil rich in organic carbon content, Simmelkær, we observed a higher degree of ageing when treated with manure. Contrarily, sorption experiments showed less sorption to Simmelkær treated with manure than the untreated soil indicating that sorption processes are not the only mechanisms of ageing. The other topsoil low in organic carbon content, Ringe, showed no significant difference in ageing between the manure-treated and untreated soil. The present study illustrates that not simply the organic carbon content influences adsorption and ageing of atrazine in soil but the origin and composition of organic matter plays an important role.
authors.affiliation: Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350, Copenhagen K, Denmark, nadia.glaesner@gmail.com.
authors.forename: Nadia
authors.initials: N
authors.lastname: Glæsner
authors.forename: Jacob
authors.initials: J
authors.lastname: Bælum
authors.forename: Bjarne W
authors.initials: BW
authors.lastname: Strobel
authors.forename: Carsten S
authors.initials: CS
authors.lastname: Jacobsen
mesh_terms: D001280:Atrazine / Q000378:metabolism*; D001673:Biodegradation, Environmental; D006540:Herbicides / Q000378:metabolism*; D008372:Manure / Q000032:analysis / Q000382:microbiology*; D011549:Pseudomonas / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D006540:Herbicides; D008372:Manure; D012987:Soil; D001280:Atrazine